If he is the nominee, and the Democrats spend a billion dollars defaming him, and receive a few billion dollars in unpaid media assistance, and throw in the usual artful lies and smears along with dragging his whole unvetted playboy life through the mud, he is likely to be viewed even less favorably afterward.
Just as Romney innoculated Obama from from the health care issue, Trump would innoculate Clinton from Bill’s womanizing, and her bimbo intimidation.
Trump's problem is that even the truth looks pretty bad, before any spice is added.
It is a non issue unless Trump is the one bringing up the issue....no other gentleman Republican is going to play it crass. That is why Trump is popular.